File > New Project >SGDK2 Sample Project
Alternatively...
The best part about SGDK2 is that you can simply import sprites, without making them yourself (I had done this for a year also)
I believe the platforming example I had used when I just started SGDK2 was the old:
http://gamedev.enigmadream.com/index.php?topic=1139.0 Credit to Jam0864, although I do believe that he's no longer with us.
It's a platformer sample with stickmen. I usually imported the sprite and had customized it to my needs.
Another project, that's not as developed as IotaBuildit, is a platformer sample that I had made myself, but it's a little more complex.
http://paradigm.heliohost.org/SGDK2/GuyWithTheHand.zipIt has the default Meatboy behaviors, spikes kill, get to a goal to next level, one hit enemy kills, infinite lives, switches that control certain timed events, etc.
Oddly enough, the maps should be pretty much drag and drop in the editor. Layers use Zposition to determine which layer is infront of another. Make sure to set your tilesizes in your tileset to the graphic sizes in the graphics sheet. I can't help much with that.. SGDK1 was the program where I had learned how to devv with maps.
So many samples sitting on my computer unfinished. One for every genre of platformer.

If you don't have a specific indie-project in mind, I would highly recommend moving towards IotaBuildIt. It will help to understand the basic mechanics of devving a platformer game.